小编For*_*ner的帖子

with engine.connect() as con:

    rs = con.execute("""
                        SELECT  datediff(STR_TO_DATE(CONCAT(year,'-',month,'-',day), '%Y-%m-%d') , current_date()) 
                        from TABLE 
                        WHERE datediff(STR_TO_DATE(CONCAT(year,'-',month,'-',day), '%Y-%m-%d') , current_date()) < 900
                        group by STR_TO_DATE(CONCAT(year,'-',month,'-',day), '%Y-%m-%d');
                    """)

我觉得编译器与'%Y-%m-%d'混淆了,我可能错了.有人可以帮助我如何避免这个错误:

类型错误:格式字符串的参数不足

我有以下数据：

我绘制了该数据的点，然后使用以下代码在图上对其进行平滑处理：

scatter.smooth(x=1:length(Ticker$ROIC[!is.na(Ticker$ROIC)]), 
  y=Ticker$ROIC[!is.na(Ticker$ROIC)],col = "#AAAAAA", 
  ylab = "ROIC Values", xlab = "Quarters since Feb 29th 2012 till Dec 31st 2016")

现在我想找到这条平滑曲线的逐点斜率。还将趋势线拟合到平滑图上。我怎样才能做到这一点？